Sumitomo Riko Company Limited

Naoki Akira

Takeru Horiuchi

Yoshihiro Saito

Shimpei Miyagawa

Shinkichi Kashihara

Kenta Nakazato

Takenori Saito

Provided is a conductive roll for an electrophotographic machine. The conductive roll is a charging roll and includes a shaft body, and an elastic body layer formed on an outer periphery of the shaft body. The elastic body layer is a crosslinked body of a composition containing a diene-based polymer (a), a sulfur or peroxide crosslinking agent (b), carbon black (c), and a coupling agent (d). (c) has a specific surface area of 40 to 300 m/g. (d) is a coupling agent having a NHRgroup and a SSOH group, or a coupling agent having a NHRgroup and an ene structure (where Ris H or a hydrocarbon group having 1 to 8 carbon atoms). The contents of (c) and (d) in the composition are respectively 10 to 45 parts by mass and 0.5 to 20 parts by mass with respect to 100 parts by mass of (a).

Conductive roll for electrophotographic machine

An elastic body layer is composed of a conductive rubber composition containing an isoprene rubber, a rubber other than the isoprene rubber, and carbon black. The elastic body layer is phase-separated into a first rubber phase containing the isoprene rubber and a second rubber phase containing the rubber other than the isoprene rubber; in the range of a 5 &#x3bc;m&#xd7;5 &#x3bc;m square of an arbitrary cross section of the elastic body layer, the area ratio of the first rubber phase is within a range of 10 to 90%. The resistance value of the elastic body layer is within a range of 1.0&#xd7;10to 1.0&#xd7;10&#x3a9;. A surface layer contains an electronic conductive agent and a crosslinked body of at least one polyurethane resin of an ether polyurethane resin and a carbonate polyurethane resin, and the glass transition point of the surface layer is within a range of &#x2212;10 to &#x2212;70&#xb0; C.

Charging roll or developing roll for electrophotographic device

Growing community of inventors

Aichi, Japan

Naoki Akira